This is a bug with the v5.1.0 release. While Autotune is properly recommending those fields to be blank, it's not currently able to 'delete' those values, only change them to other ones. We'll be releasing a v5.1.1 release over the next few days that should fix that problem.
Until then, I wouldn't worry about it. The deletion of those fields is a recommendation since your site doesn't have SSL and it's best to not enable features you can't use. It won't affect your functionality though.
I hope that helps,
Alex